2Melt the butter in a saucepan over low heat; add the garlic and cook for 30 seconds.
3Add 3/4 cup of the stock and the tomatoes.
4Bring to a boil.
5Reduce the heat and simmer, uncovered, over medium heat for about 10 minutes or until the tomatoes are tender.
6Add the cream and bring to a boil, stirring.
7Simmer over medium heat until the sauce is thick enough to coat the back of a spoon.
8(The sauce can be kept, covered, for 1 day in the refrigerator. Heat again over low heat.)
9Sprinkle the chicken with salt and pepper on both sides.
10Heat the oil in a large, heavy skillet over medium-high heat.
11Add the chicken and saute, pressing on the chicken occasionally with a slotted spatula, for about 4 minutes per side or until the meat feels springy and is no longer pink inside (cut to check).
12Transfer to a board; cover and keep warm.
13Discard the fat from the skillet.
14Add the remaining stock and bring to a boil, stirring up the pan juices.
15Boil to reduce slightly, then add to the sauce.
16Stir in the basil.
17Taste and adjust the seasoning.
18Meanwhile, cook the pasta, uncovered, in a large port of boiling salted water over high heat, stirring occasionally (about 1 to 2 minutes for fresh or 3 to 5 minutes for dried fettucine), or until tender but firm to the bite (al dente).
19Drain, transfer to bowl and toss with 3 or 4 tablespoons of the sauce.
20Cut each chicken breasts into 2 or 3 diagonal slices.
21Reheat gently in the sauce if needed.
22Transfer the pasta to serving plates, top with the chicken and coat with sauce.